Diethylaminosulfur trifluoride (DAST) is a very powerful reagent that allows the conversion of various alcohols to fluorine-containing products which can possess interesting biological activities. The fluorination process can occur in unison with a ring-expansion and/or ringcontraction.

Diethylaminosulfur trifluoride (DAST) is a very powerful reagent that allows the conversion of various alcohols to fluorine-containing products which can possess interesting biological activities. The fluorination process can occur in unison with a ring-expansion and/or ring-contraction.